gnu: Add go-go-opentelemetry-io-otel-exporters-prometheus.

* gnu/packages/golang-web.scm (go-go-opentelemetry-io-otel-exporters-prometheus): New variable.

Change-Id: I11d062be1a55a4d374741e35060be5cf0e19055b

gnu/packages/golang-web.scm

@@ -16634,6 +16634,61 @@ protobuf payloads.  By default the telemetry is sent to
 @@url{https://localhost:4318/v1/traces}.")
     (license license:asl2.0)))
 
+(define-public go-go-opentelemetry-io-otel-exporters-prometheus
+  (package
+    (name "go-go-opentelemetry-io-otel-exporters-prometheus")
+    (version "0.62.0")
+    (source
+     (origin
+       (method git-fetch)
+       (uri (git-reference
+              (url "https://github.com/open-telemetry/opentelemetry-go")
+              (commit (go-version->git-ref version
+                                           #:subdir "exporters/prometheus"))))
+       (file-name (git-file-name name version))
+       (sha256
+        (base32 "0ag8103mf4j03lspi5rxk161iscbw1wkdk6ri9f746jia1w4qji8"))
+       (modules '((guix build utils)
+                  (ice-9 ftw)
+                  (srfi srfi-26)))
+       (snippet
+        #~(begin
+            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
+            ;; Consider to implement it as re-usable procedure in
+            ;; guix/build/utils or guix/build-system/go.
+            (define (delete-all-but directory . preserve)
+              (with-directory-excursion directory
+                (let* ((pred (negate (cut member <>
+                                          (cons* "." ".." preserve))))
+                       (items (scandir "." pred)))
+                  (for-each (cut delete-file-recursively <>) items))))
+            (delete-all-but "exporters" "prometheus")
+            (delete-all-but "." "exporters")))))
+    (build-system go-build-system)
+    (arguments
+     (list
+      #:import-path "go.opentelemetry.io/otel/exporters/prometheus"
+      #:unpack-path "go.opentelemetry.io/otel"))
+    (native-inputs
+     (list go-github-com-stretchr-testify))
+    (propagated-inputs
+     (list go-github-com-prometheus-client-golang
+           go-github-com-prometheus-client-model
+           go-github-com-prometheus-otlptranslator
+           go-go-opentelemetry-io-otel
+           go-go-opentelemetry-io-otel-metric
+           go-go-opentelemetry-io-otel-sdk
+           go-go-opentelemetry-io-otel-sdk-metric
+           go-go-opentelemetry-io-otel-trace
+           go-google-golang-org-protobuf))
+    (home-page "https://go.opentelemetry.io/otel")
+    (synopsis "OTLP Prometheus Exporter")
+    (description
+     "Package prometheus provides a Prometheus Exporter that converts OTLP
+metrics into the Prometheus exposition format and implements
+prometheus.Collector to provide a handler for these metrics.")
+    (license license:asl2.0)))
+
 (define-public go-go-opentelemetry-io-otel-exporters-stdout-stdouttrace
   (package
     (name "go-go-opentelemetry-io-otel-exporters-stdout-stdouttrace")